Inboard diesel hull with an outboard, consumption/performance ?

[scoutabout]

Re: Inboard diesel hull with an outboard, consumption/performance ?

Looks like a great boat and project, headlight.

One element that may bear some consideration is the different weight distribution your outboard setup will in on that hull. I'm certainly no naval architect but I wonder if you need some kind of confirmation that hanging a big outboard way out back isn't going to do strange things to the ride and handling of a boat designed to have a huge heavy lump of an engine set much lower and further forward. (Actually, I'm surprised this isn't the argument your hull dealer seized upon to try to make the diesel sale...)

 

[headlight]

Re: Inboard diesel hull with an outboard, consumption/performance ?

Looks like a great boat and project, headlight.

One element that may bear some consideration is the different weight distribution your outboard setup will in on that hull. I'm certainly no naval architect but I wonder if you need some kind of confirmation that hanging a big outboard way out back isn't going to do strange things to the ride and handling of a boat designed to have a huge heavy lump of an engine set much lower and further forward. (Actually, I'm surprised this isn't the argument your hull dealer seized upon to try to make the diesel sale...)

Hi scoutabout, I have researched this very thing & it all seems good.
Speaking to a few inboard diesel engined owners who have had more than one of this model they state that older models handled & rode better.
They claim that this is because the older boats used heavier engines & also that on later hulls the fuel tanks are set further forward.
These 2 things make the boat ride slightly bow down.
By having the big OB set back off the transom & utilising the engine bay to accomodate the fuel tanks the weight distributionl should be similar to the older earlier model.
If I need to however I can move weight forward by putting the tanks where they are sited in the new inboard models.
The chap I have spoken to who is running the Optimax powered hull has also had an early inboard model & a later inboard model.
Of the 2 inboard models he also states that the earlier one handled better & says that the OB one he is running now handles the best of the 3 as in effect the hulls waterline is nearly 3ft longer so it rides more like a 26 footer.
The deck space with the OB is massive as the engine box for a 240hp inboard is obviously quite big on a 23ft hull & encroaches a lot.
If I was doing a lot of hours I could see the advantage of diesel but the most hours I have done in a year over the past 4 years, due to work & weather has been 125 so even my estimate of 150 hours may be optimistic.
To me on this size, type & weight of hull the OB option is a no brainer & I will definately be ordering a hull after Christmas.

headlight

 

[PS94]

Re: Inboard diesel hull with an outboard, consumption/performance ?

I can't recall who, or where, but it was on here (obviously) a fellow stripped out an inboard, and made a really nice set-up with splashwell for his outboard...I think he was an aluminum welder, or at least did one heck of a job..would be worth talking to him about his swap....

 

[headlight]

Re: Inboard diesel hull with an outboard, consumption/performance ?

Well I have just got off the phone to the boat builders, who I rang to find out their up to date hull price, & they have informed me that they have just started building the hull with a purpose built splashwell so that they can have outboards fitted!
Seems that I am not the only one thinking along these lines then.
I have to decide now whether to go for a splashwell hull or the standard hull & fit an engine pod.
Downside of the splashwell is that I will lose some deck space at the centre of the stern.

headlight

 

[scoutabout]

Re: Inboard diesel hull with an outboard, consumption/performance ?

Thanks for the reply, hl - very interesting. It's funny you mention the comparison between the later and earlier fit-up because I was thinking the boats in the pics look like they are riding ever so slightly bow down. I dismissed it as an illusion due to the cabin-forward design.

At any rate, in light of your research I think I'd choose the standard hull with engine pod and locate the fuel tanks aft. Whatever your choice, I can't wait to see some pics come launch day!

(I will also choose this moment to insert a shameless plug for Yamaha power. I certainly love mine.)

 

[headlight]

Re: Inboard diesel hull with an outboard, consumption/performance ?

I like Yams scoutabout & have had 7 or 8 over the years with no troubles.
My last 2 engines have been Honda"s & I must say that I think they are every bit as good as a Yam.
Here in the UK a 225hp Honda fitted is ?13k & 225hp Yam fitted is ?16k.
I just don"t see that the Yam is worth the extra ?3k.

headlight